This invention relates to a device for taking up slack and applying constant tension on a conveyor belt or chain and more particularly but not by way of limitation to a device hydraulically operated which applies continuous and adjustable pressure on take-up bearings surrounding a take-up shaft mounted at one end of the conveyor.
Heretofore, there have been conveyor take-up devices having adjusting screws for the proper positioning of the bearings mounted on a take-up shaft. Also, there are take-up devices which use counter weights for providing a constant automatic adjustment. The adjusting screws quite often present the problem of over-stressing the conveyor belt or chain where the adjusting screws have been turned too far with a hand tool. Further a maintenance mechanic has the problem of not knowing when he has adjusted the screw to the proper tension on the belt or chain. Another problem is that after the chain or belt has stretched or worn slightly, the chain or belt becomes slack. This can cause the belt to slip at the driven sprocket causing damage to the belt or sprocket and even cause a fire or explosion. The slack in the chain can also cause the chain to ride around the drive sprocket too far and damage the chain, sprocket and other parts of the conveyor.
The counter weight used for applying tension on a conveyor is bulky in size and in many applications there is not enough space to accomodate the take-up weights. Also, this type application has the disadvantage in that it is difficult to adjust the tension on the belt or chain because it is difficult to remove or add bulky weights. Another disadvantage is sudden starts cause the weights to suddenly rise and fall throwing a shock load on the belt or chain.
There are various types of take-up systems for conveyors disclosed, for example, in U.S. Pat. No. 2,788,883 to Schwenk, U.S. Pat. No. 2,815,853 to Likens, U.S. Pat. No. 2,986,267 to Carlson et al, U.S. Pat. No. 3,638,781 to Comley, U.S. Pat. No. 3,765,525 to Hartwig and U.S. Pat. No. 3,777,879 to Dehne. None of these prior art patents specifically disclose the unique features of the subject hydraulic take-up device. The subject hydraulic take-up device eliminates the above mentioned problems inherit in the prior art take-up device.